KDX
I have and use the 257 AI solely for coyotes. It’s a custom 24” SSK barrel with brake (1-10” twist) for the TC-Encore frame. A Burris FF-II 3.5 x 14 Ballistic Plex sets on top.
I make the brass out of the parent 7x57 Mauser. My pet load is 48.5 grains of Vhit N-150, CCI-200, 75 grain Vmax. These run 3636 fps and print .990” @ 200 yards from the bench.
I have taken coyotes from 38 to 168 yards with this load. All bang flop. None of the bullets have exited, the one taken broadside at 38 yards, did produce a 5” blow back entry hole.
Good luck with your project.
B..
